// 2025/11/16
// 编辑距离

class Solution {
public:
    int minDistance(string word1, string word2) {
        int n1 = word1.size(), n2 = word2.size();
        vector<vector<int>> dp(n1 + 1, vector<int>(n2 + 1, 0));
        for(int i = 0; i <= n1; i++)
            dp[i][0] = i;
        for(int j = 0; j <= n2; j++)
            dp[0][j] = j;
        for(int i = 1; i <= n1; i++)
        {
            for(int j = 1; j <= n2; j++)
            {
                dp[i][j] = dp[i - 1][j - 1];
                if(word1[i - 1] != word2[j - 1])
                    ++dp[i][j];
                dp[i][j] = min(dp[i][j], min(dp[i - 1][j], dp[i][j - 1]) + 1);
            }
        }
        return dp[n1][n2];
    }
};